Beer tap cap



FIG. 1 is a perspective view showing my new design;

FIG. 2 is a top view thereof;

FIG. 3 is a side view thereof; and,

FIG. 4 is a bottom view thereof.

The broken line in FIG. 2 defines the boundary of the claimed design and forms no part of the claimed design. 

The ornamental design for a beer tap cap, as shown and described. 